Method of producing lower alcohols from glycerol

Abstract

This invention relates generally to a process for value-added processing of fats and oils to yield glycerol and glycerol derivatives. More particularly, the process converts glycerol to acetol and then acetol to propylene glycol to produce a propylene glycol with ultra-low amounts of ethylene glycol. The propylene glycol thus produced may be used as an antifreeze, deicing compound, or anti-icing compound.

I claim: 
     
       1. A gas phase reaction process for converting glycerol to a product at high selectivity to propylene glycol and low selectivity to ethylene glycol, comprising:
 providing a gas phase reaction mixture that is essentially free of liquid and contains 
 glycerol with a partial pressure of glycerol in a range from 0.01 bars and 0.5 bars of glycerol, and 
 hydrogen with a partial pressure of hydrogen between 0.01 and 5 bars of hydrogen, 
 wherein the partial pressure of glycerol in the reaction mixture is less than glycerol's dew point partial pressure in the reaction mixture, and greater than one fourth the dew point partial pressure in the reaction mixture; 
 maintaining the reaction mixture a total pressure between 0.02 and 5 bars; 
 contacting the reaction mixture with heterogeneous catalyst containing one or more elements of the subgroups from Group I, Group VI, and/or Group VIII of the Periodic Table at a temperature between 150° C. and 280° C. to form propylene glycol. 
 
     
     
       2. The process of  claim 1 , wherein the catalyst comprise at least one metal selected from the group consisting of platinum, palladium, ruthenium, chromium, nickel, copper, zinc, rhodium, chromium, and ruthenium.